All these posts have been very interesting - thank you everybody!
Personally, I could never ever take away a life, no matter what the circumstances. Even in self-defence, I'd be horrified if I'd actually killed my attacker. A bash over the head with my big frying pan, but not fatally. Even, over the years, having to sit beside each of our much-loved cats in their frail old-age while the vet put them to sleep caused me agony of heart.
So I could never condone the Death Penalty for convicted criminals. I realise the general public has to be protected from murderers etc, and life imprisonment seems the best way. The inmates of he eight prisons I visited seemed to adapt to prison life. It wasn't fun of course, but they were all well looked-after.